# NTSB SEA06CA165: Bell 407, N407SH, Havre, MT, August 19, 2006

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: August 19, 2006, 11:55 local (17:55 UTC)
- Place: Havre, MT
- Coordinates: 48.190261, -114.379692 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.1903&lon=-114.3797&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report November 29, 2006
- Report: Approved by Office Director
- NTSB case key (mKey): 64361
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA06CA165
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/64361/pdf
- Page: https://openairdocs.org/ntsb/SEA06CA165

## Probable cause

The pilot inadvertently allowing the helicopter to enter into a vortex ring state (settling with power) condition while he was lowering a long-line load to the ground, resulting in the helicopter settling to the ground and its tail rotor impacting part of the rigging used to haul the load. Factors include the long-line load and its rigging sitting on the ground at the point where the helicopter settled to the terrain.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- In flight collision with object, approach
  - settling with power - inadvertent, pilot in command (cause)
  - clearance - not maintained, pilot in command (cause)
  - object - other (contributing factor)

## Analysis

The pilot, who was approaching an area where he was going to place a long-line load onto the terrain, inadvertently allowed the helicopter to enter into a vortex ring state (settling with power) condition, resulting in his inability to keep the helicopter from descending at a rate that resulted in it hitting the ground and bouncing back into the air. At the point in time when it contacted the ground with its skids, the helicopter's tail rotor impacted a portion of the rigging for the load that it had been hauling, which resulted in substantial damage to the tail rotor and the tail rotor drive shaft.

## Factual narrative

The pilot, who was approaching an area where he was going to place a long-line load onto the terrain, inadvertently allowed the helicopter to enter into a vortex ring state (settling with power) condition, resulting in his inability to keep the helicopter from descending at a rate that resulted in it hitting the ground and bouncing back into the air. At the point in time when it contacted the ground with its skids, the helicopter's tail rotor impacted a portion of the rigging for the load that it had been hauling, which resulted in substantial damage to the tail rotor and the tail rotor drive shaft.

## Aircraft

- Registration: N407SH (not matched to a registry record)
- Reported make and model: Bell 407
- Category: Helicopter
- Serial number: 53045
- Engines: Rolls-Royce 250 C47B turbo shaft
- Damage: Substantial damage
- Flight: External load, Part 133
- Operator: Silver State Helicopters
- Registered owner: Silver State Helicopters
- Airworthiness certificate: Standard, Normal
- Departed: KHVR, Havre, MT
- Destination: Havre, UT

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; commercial, flight instructor; instrument ratings: helicopter; medical: class 2; flight hours: 1,720 total, 75 in this make and model, 100 in the last 90 days, 45 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Lowest ceiling: none
- Temperature: 77 °F

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20060819017659A](https://openairdocs.org/incident/20060819017659A), Aug 19, 2006: Bell 407, Havre, MT, Substantial damage. (-23) During an approach to an unimproved landing area, the aircraft entered into a rapid descent, beginning at 75 feet AGL, that resulted in a hard landing.…

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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